Secondhand shopping is in the throes of a tech-driven seismic shift, one that is quickly making the gently worn and just-like-new not simply equal in stature to off-the-rack items, but arguably more desirable. How much more would you want that Prada purse or perfect vintage fedora if it were from the closet of your favorite fashion blogger or among favorite items selected by a stylist to A-list stars?

At the same time, fashion-minded startups are pursuing new ways to connect buyers and sellers online in a space that's been stagnant for years.

"EBay today looks frighteningly similar to eBay in 1999, and Craigslist looks like a newsgroup," says Jim Rose, co-founder of San Francisco's Copious, an online marketplace with a Pinterest-style layout that matches shoppers with new and used items based on trends and people they follow.

Recently tapping fashion bloggers such as Man Repeller and Because I'm Addicted to sell their preloved clothing and accessories through its platform, Copious is just one example of secondhand style's new look. The RealReal, Poshmark and Threadflip are also turning secondhand fashion into an evermore stylish, entertaining and increasingly social pursuit.

The RealReal

An unmarked unit in a nondescript office park 13 miles north of the Golden Gate Bridge seems an unlikely place to find a $17,500 Hermès Birkin bag or a rack of Chanel items the length of a Google shuttle bus.

But that's what's inside the filled-to-the-gills offices of the RealReal, a website selling pre-owned luxury women's apparel and accessories through 72-hour flash sales.

"We literally have some of the wealthiest women in the world's clothing coming in here," says co-founder and CEO Julie Wainwright, once the chief executive of Pets.com, an Amazon-backed company whose demise became the stuff of bust-era legend.

Launched in June, the RealReal accepts designer labels, often sent by way of high-profile stylists on behalf of anonymous celebrity clients. In a 2.0 version of the traditional consignment model, the company then inspects, photographs, prices and lists items in exchange for a 40 percent cut of the sale.

"We have a different twist on an old business," Wainwright says.

With nearly 20 employees sharing an office the size of a modest conference room, Wainwright is prepping to move to a new Sausalito location capable of housing enough boxes of Blahniks and Louboutins and racks of Burberry, Balenciaga and Celine to satisfy the appetites of the site's 65,000 members.

"The industry's image has gotten a boost from some reality shows that follow resellers and their upscale customers," says First Research's Linnea Kirgan, a specialist on the $16 billion used-merchandise retail industry, of which about 15 percent, or about $2.4 billion, is women's clothing and accessories.

The question is how to create marketplaces that will not only draw more of that $2.4 billion online, but also attract new populations of buyers and sellers.

Poshmark

Launched in December with $3.5 million in funding led by Mayfield Fund, Menlo Park's Poshmark allows iPhone users to download its mobile app, snap images of clothing and accessories, and quickly post them for others to like, comment on, share on social networks or buy.

"We've had women who've downloaded the app at 10 o'clock, uploaded their first items by noon and shipped their items by 4 p.m.," relates co-founder and CEO Manish Chandra, also founder of Kaboodle (now owned by Hearst).

Weeknight Posh Parties invite members to open the app at designated times to buy and sell items grouped into themes like pop of color, wild things and statement jewelry. When an item is purchased, Poshmark processes payment, takes 20 percent of the sale and sends the seller a shipping label.

"The entire platform is built around a social architecture," Chandra says.

And while socializing is part of the in-app culture, users are doing more than just chatting. About $250,000 in new merchandise is uploaded each week, with the average item priced at $50. Poshmark declined to give exact numbers but says user count doubles monthly and transactions double every two weeks.

Socializing in a virtual space may be part of the experience, but the ease with which users can buy and sell is, perhaps, even more of a draw.

"If I'm able to sell through my phone, and I don't have to walk out my door, it saves me time, and it's convenient," says Jeanne Chan, who runs the blog Shop Sweet Things and has sold a Louis Vuitton bag and Michael Kors boots using Poshmark.

Threadflip

Another secondhand-style hub attracting bloggers and high-tech fashion fans is Threadflip, a San Francisco startup launched in April with $1.6 million in funding led by First Round Capital and Baseline Ventures. The company recently hired Going West blogger Jennie Lodge as a brand manager and features items owned by popular bloggers, including Brit Morin of Hello Brit, Late Afternoon's Liz Cherkasova and Laura Ellner of On the Racks.

Threadflip's 5,000 members join by connecting their Facebook profiles and completing a short style survey and shop by scrolling a continuously refreshed grid of images displayed in a Pinterest-style format. The company is betting that its attractive layout and features designed to make selling quick and easy will appeal to those who might shy away from eBay and Craigslist.

"What's happened over the years with marketplaces is that they cater primarily to power sellers, people who have the time and the resources to set up shop. We truly want to build a P2P (person-to-person) platform where an everyday woman seamlessly can use it," explains co-founder and CEO Manik Singh, formerly a vice president at the Sean Parker-founded philanthropy site Causes.

Threadflip allows members to upload images directly from Facebook and sends sellers a box, wrapping paper and a prepaid shipping label to package and send items. The company is experimenting with a White Glove Service option that functions much like the RealReal's consignment model. Send in items and agree to part with 40 to 50 percent of the sale price versus the 15 percent taken for other transactions, and Threadflip will handle the styling, photography and merchandising and send you a check once items sell.